The principal objectives of this project are to identify antiplaque and anti-caries agents suitable for short-term clinical investigation and to develop methods for assessing these agents. Screening is conducted both in vitro and in animals. The in vitro studies include measurement of the minimal inhibitory concentration and midification of enamel dissoultion rate conferred by the test agent. The animal studies measure the effects of an agent on dental caries and plaque. Investigation continues on three agents that purportedly do not stain. The bispyridine is ready for clinical evaluating. The remaining two agents are being screened in animals for their effects on dental plaque and caries.